Color and odor stabilized dry aerosol antiperspirant

ABSTRACT

Dry aerosol antiperspirant compositions containing hexachlorophene and/or perfumes which are subject to deterioration and are stabilized by the incorporation of a small amount of citric acid.

United States Patent 1 Wahl [ 1 Apr. 3, 1973 [54] COLOR AND ODORSTABILIZED DRY AEROSOL ANTIPERSPIRANT [75 Inventor: Errol II. Wahl,Cincinnati, Ohio [73] Assignee: The Procter & Gamble Company,

Cincinnati, Ohio [22] Filed: July 30, 1970 [21] Appl. No.: 59,691

[52] US. Cl. ..424/46, 424/47, 424/65, 424/66, 424/67, 424/68, 424/69,424/357,

[51] Int. Cl. ..A6lk 7/00 [58] Field of Search ..424/47, 45, 68, 69, 46

OTHER PUBLICATIONS Lester et al., Handbook of Cosmetic Materials, 1954,pp. 96,

Sagarin, Cosmetics Science and Technology, 1957, pp. 1,035, 1,053 and1,067.

Winter, Handbuch Der Gesamten Parfumerie Und Kosmetik, 1952, pp. 156 and675.

Primary Examiner-Albert T. Meyers Assistant ExaminerVera C. ClarkeAttorney-Richard C. Witte and Robert B. Aylor [57] ABSTRACT Dry aerosolantiperspirant compositions containing hexachlorophene and/or perfumeswhich are subject to deterioration and are stabilized by theincorporation of a small amount of citric acid.

1 Claim, No Drawings COLOR AND ODOR STABILIZED DRY AEROSOLANTIPERSPIRANT BACKGROUND OF THE INVENTION 1. Field of the InventionThis invention relates to aerosol antiperspirant compositions of thetype which are essentially anhydrous, i.e., containing only a smallamount of water. Specifically, this invention relates to suchcompositions containing materials such as hexachlorophene and perfumeswhich tend to deteriorate during storage.

2. Prior Art Combinations of hexachlorophene and citric acid in soliddetergent compositions are disclosed in British Pat. No. 786,285. It isalso known that dicarboxylic acids such as oxalic, sebacic, adipic andmalonic acids are useful in preventing the color degradation of barsoaps containing hexachlorophene upon exposure to light; see, e.g., U.S.Pat. No. 3,085,066. Salts of citric acid have also been disclosed forthis same purpose; see e.g., U.S. Pat. No. 2,970,917 which disclosesdihydrazinium and monohydrazinium citrates in soap bars containinghexachlorophene. Antiperspirant compositions have been disclosedcontaining astringent salts, hexachlorophene, a perfume, and tartaricacid; see, e.g., U.S. Pat. No. 3,509,253. Citric acid has been disclosedas a metal scavenger to protect vitamins and other oxygen-sensitivematerials.

SUMMARY OF THE INVENTION This invention relates to dry aerosolantiperspirant compositions consisting essentially of:

A. From about 1 percent to about 12 percent by weight of a finelydivided astringent comprising an acidic, metallic salt that is insolublein the composition;

B. From about 0.1 percent to about percent by weight of a suspendingagent for the astringent;

C. From about 1 percent to about 15 percent by weight of a carrierliquid of low volatility;

D. From about 0.1 percent to about 1.5 percent by weight ofhexachlorophene;

E. From about 0.005 percent to about 0.5 percent by weight of citricacid;

F. A solvent for the citric acid in an amount sufficient to dissolve atleast a portion of the citric acid; and

G. The balance, an anhydrous liquefiable propellant in an amountsufficient to produce an aerosol spray.

THE ASTRINGENT SALT Suitable antiperspirant compounds for use in thisinvention can be any of those well known in the art that are insolublein the aerosol composition as a whole. Generally, these are acidic,metallic salts, often of aluminum, zirconium or zinc. Most preferably,aluminum chlorhydroxide (ACI-I) is used, although other astringent saltsare also suitable. Examples of other salts are aluminum chloride,aluminum sulfate, aluminum oxychloride, aluminum oxysulfate, zirconylchloride, zirconyl hydroxychloride, zirconium oxychloride, zinc sulfateand zinc sulfocarbolate. Many inorganic-organic mixtures and complexesare also known in addition to the simple antiperspirant salts. Examplesof these are zirconium salt/ amine/ and amino acid complexes as taughtby Siegal in U.S. Pat. No. 3,407,254 (Oct. 22, 1968); zirconiumsalt/aluminum chlorhydroxide/glycol complexes as taught by Jones et al.in U.S. Pat. No. 3,405,153 (Oct. 8, 1968); and aluminum chlorhydroxide/glycol complexes as taught by Jones et al. in U.S. Pat No. 3,402,932(Jan. 7, 1969). Other complexes which can be used include those aluminumchlorhydroxide/zirconyl hydroxychloride complexes disclosed in theco-pending application of Raymond E. Bolich, Jr., Ser. No. 59,690, andthe aluminum hydroxide/zirconyl hydroxychloride/amino acid complexesdisclosed in the co-pending application of Wilmer L. Luedders, Ser. No.59,693, said applications being filed concurrently herewith. The latterapplication is now abandoned. These applications and patents areincorporated herein by reference.

Commercial availability of the above astringent salts is widespread, andthe choice of the desired antiperspirant compound is limited only byfactors well known to those skilled in the art. As heretofore discussed,the above-mentioned aluminum salts are preferred, and for the purposesof the present invention, aluminum chlorhydroxide and the complexesdescribed in the applications of Bolich and Luedders filed concurrentlyherewith, are especially preferred,

In dry aerosol antiperspirant compositions, the antiperspirant active isdispersed as a finely divided powder. The powder must be in the form ofa uniform size particle and must be small enough to remain suspended inthe composition within the aerosol container and to pass through thevalve without clogging. The particle size must also be such that theantiperspirant is adequately dispersed on the skin and reacts rapidlyenough with the moisture of the skin and air to convert theantiperspirant compound in dry powder form into the ionic state which isneeded for effectiveness in suppressing perspiration. In thisconnection, the emollient-carrier of the present invention which will bediscussed in more detail hereinafter is also a very important part ofthis mechanism.

Particle sizes smaller than about microns have been found to be suitablefor the practice of the present invention. Preferably, particlesaveraging from about 10 microns to about 26 microns are desirable.Normally, from about 1 percent to about 12 percent by weight of thecomposition is a desirable amount for perspiration control. Below about2 percent, the antiperspirant effectiveness drops off, while above about12 percent is not practical because the antiperspirant effectivenessdoes not increase commensurate with the additional quantities used, andin addition, the viscosity of the product increases so that handling ismore difficult and atomization is less satisfactory. The most preferredrange is from about 2.5 percent to about 6 percent.

THE SUSPENDING AGENT The suspending agent can be any of those which havebeen disclosed in the prior art. Suitable examples include: a colloidalsilica such as Cab-O-Sil, a pyrogenic silica having a particle diameterbetween about 0.001 and 0.03 microns as disclosed in British Pat. No.987,301, and British Pat. No. 1,167,173; finely divided hydrophobicclays such as a reaction product of a clay such as Bentonite anddimethyldistearyl ammonium chloride (Bentone 34 or Bentone 38) asdisclosed in British Pat. No. 1,167,173; those nonionic suspendingagents disclosed in U.S. Pat. No. 3,014,844; those suspending agentsdisclosed in US. Pat. No. 3,218,262; those aliphatic monoalkylol amides(C C acyl; C C alkylol) disclosed in the co-pending application ofDouglas L. Dannemann and Jerry J. Yetter, Ser. No. 888,958, filed Dec.29, 1969, now abandoned; and those primary aliphatic amines (C Cdisclosed in the co-pending application of Charles L. Scripps and JerryJ. Yetter, Ser. No. 888,959, now abandoned filed Dec. 29, 1969. All ofthe above patents and applications are specifically incorporated hereinby reference. The preferred suspending agent is Bentone in an amountfrom about 0.1 percent to about 1.5 percent, preferably in an amountfrom about 0.3 percent to about 0.75 percent, and most preferably fromabout 0.4 percent to about 0.6 percent.

THE CARRIER LIQUID A carrier liquid of low volatility is used in theinstant invention so that the stream issuing from the aerosol containeris a moist spray rather than a gritty, dusty cloud. This imparts acosmetic feeling to the skin when applied thereto an reduces thelikelihood of breathing the otherwise dry powder. The carrier liquidalso aids efficacy be keeping the antiperspirant compound in contactwith the skin so that it does not flake off or wash off. Thus, thecarrier liquid is needed for practical use of the instant inventionthough it is not required per se for purposes of preparing a dry powderantiperspirant composition in stable form. The carrier liquid alsodecreases the vapor pressure of the propellant mixture which isdesirable.

Any of the carrier liquids that are known in the art are suitable forthe compositions of the instant invention. Examples are carboxylicesters like isopropyl myristate and isopropyl palmitate; hydrocarbonslike mineral oil and tetradecane; alcohols such as lauryl alcohol,hexadecyl alcohol, and oleyl alcohol; carboxylic acids such as lauricand oleic acid; lanolin and its derivatives such as acetylated lanolin;and silicone oils such as dimethylpolysiloxane. Other operable carrierliquids are more hydrophilic than the above-mentioned compounds, forexample, organic compounds containing multiple ester groups. Thisincludes, but is not limited to, diesters of dibasic organic acids.Examples of compounds containing multiple ester groups that are suitablefor the instant invention are di-n-octyl-n-decyl phthalate, di-n-octylphthalate, di-n-hexyl phthalate, di-n-butyl phthalate, diethyl sebacate,diisopropyl adipate, and ethyl ethylcarbomethyl phthalate [orthoC,H,OOC--COOCH COOC l-l,,].

Still other operable carrier liquids are even more hydrophilic thanthese esters. Among them are polyethylene glycol monolaurate andbutoxypolyoxyethylene oxypropylene glycols [the Ucon 50 HB series; TradeMark Union Carbide].

Among these various carrier liquids, carboxylic esters having from about12 to about 26 carbon atoms are preferred. As described supra, they canbe either aliphatic or aromatic and can contain either one ester groupor multiple ester groups. Especially preferred are di-n-butyl phthalate,diethyl sebacate, diisopropyl adipate, and ethyl ethylcarbomethylphthalate.

Any of the carrier liquids described supra can be used in amounts fromabout 1 percent to about 15 percent. Below about 2 percent, the carrierliquid is insufficient to form a moist spray and the spray is,therefore, undesirably dusty and gritty and does not adhere well to theskin. Above about 15 percent, the composition deposited upon the skinfeels undesirably oily and greasy. Amounts of carrier liquid from about6 percent to about 10 percent are preferred.

THE I'IEXACI-ILOROPI-IENE 2,2'-dihydroxy-3,5,6,3-,5',6-hexachlorodiphenylmethane (hexachlorophene) is a well-knownantibacterial agent. Recently, hexachlorophene has been incorporated insmall amounts in dry aerosol antiperspirant compositions of the typedisclosed herein. When it is incorporated in such antiperspirantcompositions, it forms a pink color upon aging. The reason for thisresult is unobvious in view of the fact that previous discolorationproblems with hexachlorophene took place in light; and these aerosolcompositions are not exposed to light. It is, of course, undesirable tohave an antiperspirant composition colored pink, since it tends todiscolor clothing and skin. It is not known what causes this pink color,but is is theorized that some kind of complex is forming between thehexachlorophene and ferric ions. Preferably, the amount ofhexachlorophene is at least about 0.05 percent and most preferably, fromabout 0.1 percent to about 0.5 percent.

PERFUME Perfumes are common ingredients of aerosol compositions; andmany common perfume ingredients such as aldehydes, cyclic materials,ketones, etc., tend to undergo reactions in the presence of, e.g., metalions, such as ferric and copper ions. This is undesirable since smallamounts of perfume ingredients can cause a very large change in theoverall odor impact of the perfume. It is believed that the citric acidalso stabilizes the perfume. The amount of perfume is preferably atleast about 0.1 percent and is most preferably from about 0.2 percent toabout 0.9 percent.

THE CITRIC ACID The hexachlorophene and the perfume are stabilized indry aerosol compositions by the inclusion of a very small amount ofcitric acid as described hereinbefore. Preferably, there is from 0.01percent to about 0.5 percent citric acid present. A preferred range isfrom about 0.01 percent to about 0.04 percent. This range is preferredsince excessive amounts of citric acid can actually cause a worse odorgrade than the smaller amounts from about 0.01 percent to about 0.04percent, although the odor grade is still better than if no citric acidwere present.

It is surprising that the citric acid is effective in an essentiallyanhydrous system and in such small amounts despite the presence of largeamounts of the astringent, etc. It is believed that citric acid isunique in this respect.

Citric acid monohydrate is preferred, since it dissolves more readily.

The solvent for the citric acid is preferably ethanol in an amount fromabout 0.25 percent to about 2.0 percent. Other solvents such asmethanol, isopropanol, propanol, etc., can be substituted insubstantially equivalent amounts. The solvent is used to predissolve thecitric acid before it is mixed into the composition.

THE PROPELLANT Any liquefiable propellant can be used in thecompositions of this invention. Examples of materials that are suitablefor use as propellants are trichlorofluoromethane,dichlorodifluoromethane, dichlorotetrafluoroethane,

monochlorodifluoromethane, trichlorotrifluoroethane,

propane, butane, and isobutane, used singly or admixed.Trichlorofluoromethane, dichlorodifluoromethane,dichlorotetrafluoroethane, and isobutane, used singly or admixed, arepreferred.

The amount of the propellant gas is governed by normal factors as wellknown in the aerosol art. It is satisfactory to consider the propellantas constituting the balance of the composition of the instant inventionthat is not accounted by the other components as detailed herein. Thepreferred limits of propellant are therefore from about 70.7 percent toabout 93.9 percent. Especially preferred limits are from about 80percent to about 92 percent.

All parts, percentages, and ratios herein are by weight unless otherwisespecified.

The following examples illustrate the invention.

EXAMPLE I An aerosol antiperspirant composition is prepared containing3.5 percent of powdered aluminum hydroxychloride which will pass througha 325 mesh screen. The composition also contains:

8.00% Isopropyl myristate;

0.60% Bentone 38;

0.10% Hexachlorophene;

0.40% Perfume;

0.27% Ethanol/H O (95:5);

0.01% Citric acid monohydrate; and

1.50% SDA No. 40 (anhydrous denatured ethanol) and the balance being apropellant mixture comprising 60 percent trichlorofluoromethane and 40percent dichlorodifluoromethane.

The above composition is prepared by dissolving the hexachlorophene inthe isopropyl myristate using a high speed mixer at a temperature ofabout 70F. The aluminum hydroxychloride is then added to the batch andmixed for about minutes at a temperature of about 70F. The Bentone 38 isnext added and mixed. Then the 95 percent ethanol is added and mixed.While the mixing continues, the temperature is slowly increased at therate of 2 to 3F. per minute, until a temperature of from about 130 to150F. is attained. The mixture is subsequently cooled to a temperatureof about 110F. while the mixing continues. The citric acid is dissolvedin the SDA No. 40 and then added to the mixture and mixed. The perfumeis then added. The mixing is continued at a temperature of from about100F. to about 110F. until the mixture becomes homogeneous. The mixtureis then allowed to cool to room temperature and is subsequently chargedinto an aerosol container. The propellant mixture is then added to thecontainer, at standard three-piece tin plated aerosol can, using anunder-the-cap filler.

The result is a highly effective powder aerosol antiperspirantcomposition for use on the skin stabilized as to color and odor ascompared with a similar composition which does not contain the citricacid.

EXAMPLE II All of the following compositions were prepared by theprocess of Example 1.

Composition 1 Aluminum chloride lsopropyl palmitate Cab-O-SilTrifluoromethylcarbanilide Perfume Hexachlorophene Citric acid,monohydrate SDA No. 40

Propellant consisting of:

20% trichlorofluoromethane; 8% dichlorodifluoromethane; 17% n-butane;and

the balance dichlorotetrafluoroethane a O Ne wn balance 0.3 0.02 1.5balance Composition 111 A mixture of aluminum oxychloride, aluminumoxysulfate, and zirconium oxychloride (2:121

A mixture of dimethylpolysiloxane,

lauric acid, and oleic acid (1:1:1)

A mixture of lauryl amine, hexadecyl amine, octadecyl amine, and

eicosyl amine (1:1:l:1)

Cab-O-Sil 0.6

Trilluoromethylcarbanilide Perfume Hexachlorophene Citric acidmonohydrate 0.

Propyl alcohol 1.

Propellant consisting of:

20% trichlorofluoromethane;

8% dichlorodifluoromethane;

17% n-butane; and

the balance dichlorotetrafluoroethane balance Composition IV A mixtureof zirconyl hydroxy- 10.0 chloride, aluminum chlorhydroxide and zincsulfocarbolate 1:1:1)

A mixture of mineral oil and tetradecane (1:1)

A mixture of Cab-O-Sil and Bentone 38 (1:1)

Hexachlorophene Citric acid monohydrate Ethanol SDA No. 40

Perfume A mixture of:

10% dichlorodifluoromethane;

20% isobutane;

20% trichlorofluoromethane; and

the balance dichlorotetratluoroethane balance 7 a 8 Com osition V All ofthe followin corn ositions were re ared ac- P g P P P cording to theprocess of Example 1. Aluminum chlorhydroxide 8.0 ia t ii e mymme 3:2Percent by Weight Hexachloro hene 0.1 Citric acid riionohydrate 0.1 5gimgfig" v I n I" W gzz it 9 hydroxychloride 3.50 3.50 3.50 3.50lsopropyl alcohol 1.50 mynsme A mixture of: n

- Bentone-38 0.60 0.60 0.60 17.15% tnchlorofluoromethane' EtOH/H 095/590 wt. 0.27 0.27 0 0.27 8.58% dichlorodllluoromethane, b l 10Trichlorgcarbanilide 010 a Geigy ca 3565* 0.10 115% "'butane; andHexachlorophene 0.2 0.2 0.10 0.10 dichlorotetrafluoroethane Citric i 4002 0A 0 Dibutylphthalate 8.00 Composition Vi SDA No. 40 1.50 1.00 2.000.25 Perfume 0.40 0.40 0.40 0.40 Acorn lex re aredb heatin 8.0% Pwiwllam1 100%} 1007510095 and g g {2 myixmre g l. Fumed aluminum oxide A1,0 ofaluminum hydroxychloride 2. 2,4,4',-tnchloro-2'-hydroxydiphenyl ether.and Zirconyl hydroxychloride, 3. CCaFICClqFz (60/40) by weight. andagitating it according to 1 Each of the above compositions is a highlyeffective app matron of Raymond E. Bolich, Jr., Sen 59,690 fil d concur.I p v dry aerosol powder antiperspirant for use on the skin, rentlyherewith which is stabilized with respect to color and odor in gggfgfg'8'? comparison with similar compositions without the Hexachlorophene0.1 citric acid. Cline What is claimed is: Methanol 0.4 Perfume 037 l. Adry aerosol antiperspirant composition consist- A mlxlglle of: ingessentially of: 17.15 trichlorofluoromethane; 858%dichlomdifluommethane; A. from about 2.5 percent to about 6 percent byMame weight of finely divided aluminum hydroxl7.l5% n butane; and yhloride; d'chlomtwaflumoethane ,/B. from about 0.3 percent to about 0.75percent by Composition v weight of a reaction product of Bentonite anddimethyldistearylammonium chloride; A 111 mixture Ofaluminum y y- 60% C.from about 0.1 percent to about 0.5 percent by chloride and the complexof ht f h m h Example lofU.S. Pat. No. 3,407,254 8 0 or01) fine, Thecomplex of Example I of the D. from about 0.01 percent to about 0.04percent by co-pending application of Wilmer weight of it i acid. L.Luedders, Ser. No. 59,693 med concurrently herewith E. from about 0.25percent to about 2 percent by g w myristate 3-2 weight of a solvent forthe citric acid selected from 'gzfi the group consisting of methanol,ethanol, Citric acid monohydrate 0.01 40 propanol and isopropanol; SDANo. 40 0.3 95% Ethyl alcohol 04% F. from about 6 percent to about 10percent by p f weight of a carrier liquid of low volatility selected Amixture of: from the group consisting of isopropyl myristate, isopropylpalmitate, di-n-butyl phthalate, diethyl ce sebacate, disopropyladipate, and ethyl ethylcar- 17-15% n-bume; and bomethyl phthalate; and

dlchlorotemfluomethane G. the balance, an anhydrous, liquefiablepropellant EXAMPLEIII All of the above compositions are desirable,effective antiperspirant compositions stabilized against odor and colorchanges as compared with similar compositions without citric acid.

